In hemiplegic patients, a motor activity, especially if it involves excessive effort, frequently results in involuntary reactions of muscle in the other limbs. The phenomenon is known as associated reaction. Associated movement of the spastic upper limb have been reported in 80% of hemiplegic stroke patients and are characterized by sudden flexion at the elbow and abduction and elevation of the shoulder. It is hypothesized that the treatment of localized muscle spasticity with type A botulinum toxin would abolish the associated reactions and improve balance and mobility. This study is designed to investigate the biomechanical change in associated reaction and spastic gait after botulinum toxin treatment.
Ambulatory hemiplegic stroke patients with significant associated reaction of the upper limb during walking were recruited at least 3 months after stroke. Type A botulinum toxin (BOTOX, Allergan) was injected into the belly of the biceps brachii and other spastic muscle of paretic upper limb. Modified Ashworth scale and modified Tardieu scale were used to evaluate spasticity. Associated reaction was evaluated by associated reaction rating scale. Vicon 460 motion analysis system was used for evaluation of the effect of the botulinum toxin on spastic gait. All the procedures of assessment were performed before and 2, 4, 6, 12 weeks after injection. Paired t test was used to compare the pre-injection and post-injection data, in order to test the effect of clinical treatment.
Ten patients were recruited in this study. The average age was 54.6 year old. Modified Ashworth scale and modified Tardieu scale of biceps brachii showed significant reduction of spasticity after treatment of botulinum toxin. The effect lasted for 12 weeks. Associated reaction during ambulation also improved after botulinum toxin injection. Gait parameters including step length and step width changed significantly after botulinum toxin injection. Joint range of motion of paretic side including shoulder abduction and adduction, shoulder flexion, extension, knee abduction and adduction also increased significantly. In our study, botulinum toxin injections in the paretic upper limb of the stroke patients not only reduce spasticity and associated reaction but also improve gait performance.
